Formation of low-frequency periodic structures in a pulsed magnetron discharge

Abstract

Periodic plasma structures are observed in non-sputtering magnetron discharge (NSMD) that is the transient quasi-stationary low-voltage regime between the high-current magnetron discharge (HCIMD) and an arc. The fast camera imaging synchronized with the magnetic probe diagnostics reveals the correlation between the observed rotation of the plasma inhomogeneities and the magnetic field perturbation behaviour. The frequencies of the periodic processes fall into kHz-range. A simple analytical model of the ionization instability in crossed electric and magnetic fields is suggested for the low-pressure discharge case. Using the model, the possible ranges of wavelengths and frequencies for the plasma inhomogeneities are evaluated. The results show good agreement between the experimental data and theory.